Improvement in centre-boards foe vessels



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IMPROVEMENT IN CENTRE-BOARDS FOR VESSELS. p

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Be it known that I, F. J. MA'CFARLAN, of San Francisco, in the county of San Francisco, and State of California, have invented a new and useful Improvement in Centre-Boards and I do hereby declare that the following is a full, clear, and exact description thereof', which will enable others skilled in theart to make and use the same, reference being had to the-accompanying drawings, forming part of `this specification.

This invention relates to the location of the centre-boards of boats and sailing-craft of all kinds, but is designed more particularly for freight-carrying vessels. It consists in employing two centreboards, and locat ing the same at the extreme' ends of the hull, as shown in the drawing, which latter is a longitudinal section of the hullof a vessel, with the centre-board casings or wells placed one in each end of the same.

`A A aretrhe wells, and B B the centre-boards, which are'raised by a rope, d, or any other known method. The keel at these points is niortised in the usual way for the reception of the centre-board, which latter is hung with a pin through it and its well, and is made to descend and present its surface below the keel for the purpose of keeping the vessel from making much leeway. l i

.I am aware that vessels have been constructed with two or more centre-boards', but the number was multi-` plied simplyto increase the effect, and while they were distributed along the whole length of the keel, the forward and after boards have never heretofore been placed in the extreme ends of the vessel.

I am also aware that a folding keel, which is made to turn up` laterally when not needed, has been'patented. This invention is not of practicable application to sea-going or coasting vessels, for the buifeting of the waves would soon destroy its, useful operation; it is, beside, attended with other disadvantages beside its frail character.

The objectof my invention is to increase the cargo-spaccia centre-board vessels by disposing of the centreboards at eachI end, where the narrowness of the hull renders the space of little value for stowage; and while i they will exert their full eiect in these locations, they will not weaken or strain the hull tosuch an extentrs is usually the' case when placed in the middle of the hull, or approximately to it. V

When the midship hold of a vessel is obstructed by the presence of centre-board wells, much inconvenience arises in the stowage or breaking out of cargo, Vparticularly lumber, railroad-iron, and any goods of long dimensions, yas theserequire a clear hold to Vadmit ot'` their easy handling and proper'stowage. Lee-boards placed out'- side the hull of vessels are used to afford a clear hold for the objects above mentioned, but these are clumsy andimperfcct expedients, and are available only for small coasters or river and harbor craft,

I .My invention obviates the use of these, and'has, beside, the following advantageous qualities, to wit:' The capacity of the hold is not invaded by the centre-board or boards. The Weatherly qualities of the vessel are made'equal to those of a keel vessel. The centre-board wells, when located in theextrerne ends of the hull, are laccessible in case of their leaking. Being located `in the strongest parts of the .liull, they are not so liable to strain the latter-and-thereby produce leakage. The Steerage of the vessel -will be improved, as the after board will tend to'prevent the sO-called griping or swinging of /the stern when running with a free wind. The area of board-surface can be lessened by my improved location of them, as in the said location they have been found by experiment to admit of a reduction in surface with effective result. It has also been found that in heavy weather the vessel -st'eers easier, requiring less helm, and behaving generally better than when the boards were placed elsewhere. This is due t0 the circumstance of the volume of the waves having passed the forward centreboard before the vessel rises upon it, and not having reached the after one while the vessel is poised on its volume, as is the case when the boards are located at or near the middle of 'the hull. The only exception to this is when the waves are striking the vessels broadside, in which case there is no'especial advantage other than the better resistance to the strain, as before mentioned.

The objectionable features of centre-boards, as heretofore placed, are chiefly the straining of thc vessel, rand consequent leakage, their encroachment upon the most valuable part of the cargo-space, the predisposition lof the vessel to roll and steer badly in rough weather. My improvement obviates these objectionable features, and supplies a desideratum long felt for sea, coast, and inland navigation by the saine vessel.

i'. claim as new, and desire to secure by Letters Patent- The location of centre-boards, or other equivalent devices for the same specific purpose, in the extreme `bow and stern of vessels, that is to say, the placing of the said'boards forward of the foremast or aft of the d vessels, and forward of the forcmast and aft of the miz'zen-mast in three-masted ves- Amainmast in two-mastc sels, substantially as shown and described, and for the objects and purposes specified.

The above specification of my'invention signed by me, this 21st day of May,.1867`.

F. J'. MACFARLAN.

Witnesses:

JAMES NICHOLS, R, P. Lewis. 

